Mini Column Tests

Chapter Ten: Experimental Procedures

Chapter Ten: Experimental Procedures

The resin loaded with copper was tapped to determine the volume and eluted with 2M H2S04to determine the amount of copper that was adsorbed onto the resin. This was done to determine the accountability for each test. The resin converted to hydrogen form was tapped and the pH was measured.

10.10 Minimum Fluidization Velocity Measurement 10.10.1 Apparatus and Equipment:

Perspex Column:

Height= 1 m

Inner Diameter= 2.4 cm Measuring cylinder (lOO mL) Watson Marlow peristaltic pump 10.10.2 Reagents:

TP 207 Iminodiacetic acid Distilled water

10.10.3 Procedure:

100 mL of tapped TP 207 resin was loaded into a perspex column and the static resin bed height of the column was measured using a ruler.Itwas determined at 203 mm. Water was used as the fluidizing liquid and the Watson Marlow peristaltic pump was started.

A volume of liquid was collected for one minute to determine the flow rate. The speed was slowly increased and the volume was collected for that time interval. The bed height was meas- ured with a ruler.

At new speed intervals the procedure was repeated to determine the minimum fluidization ve- locity.

Figure 10.3: Photograph ofthe Watson Marlow PeristaIticPump

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 52

Chapter Ten: Experimental Procedures

10.11 Column Tests

The column tests were conducted at three different superficial linear velocities to determine the effect of an increase in linear velocity on the height of the mass transfer zone. The heights of the resin bed was varied to accommodate the mass transfer zone at each linear velocity. From the mini column tests one pH solution and one form of resin was chosen for testing.

10.11.1 Apparatus and Equipment:

3 perspex columns:

Height= 1 m

Inner Diameter= 2.4 cm

Measuring cylinder (500, 1000,2000 mL) Watson Marlow peristaltic pump

pH meter Spatula Stirrer Pill vials

10.11.2 Reagents:

TP 207 Iminodiacetic acid Distilled water

H1S04

CuS04.5H10 10.11.3 Procedure:

Three volumes of resin were used for the test namely 406,814, and 1626 mL. The TP 207 resin in the H+ form was tapped to the above mentioned volumes and the pH measured.

For Column test 1

The 406 mL resin was loaded into a 2.4 inner diameter and Im height column. 3 glL of Cu1+

from a copper sulphate solution was made up. Concentrated H1S04 solution was added to the feed solution to drop the pH to 3. A Watson Marlow peristaltic pump was used to set the re- quired flow rates.

Copper solution was passed down flow through the inlet of the column at the required flow rate.

200 mL of the effluent was collected at the bottom of the column with a measuring cylinder.

The pH and the flow rate of the effluent were monitored throughout the test. The effluent was A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 53

Chapter Ten: Experimental Procedures

sampled and analyzed for Cu²+ to determine breakthrough through the resin bed. The samples were analyzed using the Atomic Absorption Spectrometry. The resin loaded with copper was tapped to determine the volume of the resin and was eluted with 2M H2S04 to determine the amount of copper that was adsorbed onto the resin. This was done to determine the accountabil- ity for each test.

The resin converted to H+ form was tapped and the pH was measured. The similar procedure was used for the 814 and 1626 mL of resin except for the 814 mL of resin two perspex columns were required and for the 1626mL of resin three perspex columns were required. The columns were run in series for the last two tests.

10.12 Pilot Plant Testing

The pilot plant testing involved operations of a fixed bed ion exchange system and a fluidized ion exchange system (Refer to Figure lOA).

For the fixed bed column the feed solution was passed through the top of the resin bed and for the fluidized bed the feed solution was passed through the bottom of the resin bed.

Two concentrations namely 6 g/L and 0.6 g/L of Cu²+solution were used for testing and com- paring the contacting equipment.

10.12.1 Apparatus and Equipment:

Fixed Bed Dimensions:

One Perspex Column Height= 1 m

Inner Diameter= 2.4 cm Fluidized Bed Dimensions:

One Perspex Column Height= 2 m

Inner Diameter= 2.4 cm Measuring cylinder (1000 mL) Watson Marlow peristaltic pump pH meter

Spatula Stirrer Pill vials

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 54

Chapter Ten: Experimental Procedures 10.12.2 Reagents:

TP 207 Iminodiacetic acid Distilled water

H2S04

CuS04.5H20

10.12.3 Procedure:

One volume of resin was used for all test work and both contacting equipment were run at the same linear velocity so that comparisons could be made.

406 mL of TP 207 resin in the hydrogen form was tapped and the pH measured.

For the Fixed bed column:

406 mL resin was loaded into a 2.4 inner diameter and lm height column (Refer to Figure 10.5). 6 glL of Cu²+from a cupric sulphate solution was made up. Concentrated H2S04 solution was added to the feed solution to drop the pH to 3. A Watson Marlow peristaltic pump was used to set the required flow rates. Copper solution was passed down flow through the inlet of the column at a linear velocity of 0.13 cm/so

200 mL of the effluent was collected at the bottom of the column with a measuring cylinder (Refer to Figure 10.6). The pH and the flow rate of the effluent were monitored throughout the test. The effluent was sampled and analyzed for Cu²+to determine breakthrough through the resin bed. The samples were analyzed using the Atomic Absorption Spectrometry.

The resin loaded with copper was tapped to determine the volume of the resin and was eluted with 2M H2S04 to determine the amount of copper that was adsorbed onto the resin. This was done to determine the accountability for each test (Refer to Figure 10.10). The resin converted to hydrogen form was tapped and the pH was measured. The similar procedure was used for the fluidized bed except the resin was loaded into a 2m long column and the direction of flow of the input solution was up flow.

The above was repeated using both contacting equipment at 0.6 g/L solution to find the effects of smaller concentrations. Again the same amount of resins was used and the same linear veloc- ity.

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 55

Chapter Ten: Experimental Procedures

Figure 10.4: Photograph of the Pilot Plant 1 - Fluidized bed column (2.4 cm id and 2 m long)

2 - Fixed bed column (2.4 cm id and 1 m long) 3 - Peristaltic Pump

4 - Tank for input solution

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 56

Chapter Ten: Experimental Procedures

Figure 10.5: Photograph ofthe Fixed Bed Column at the Startof Operations

Figure 10.6: Photograph of the Fixed Bed during Operation with Copper loading onto the resin

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 57

Chapter Ten: Experimental Procedures

Figure 10.7: Photograph of the Fixed Bed at the End of Operation with resin fully loaded with copper

Figure 10.8: Photograph of the Fluidized Bed during Operation with Copper loading onto the resin

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 58

Chapter Ten: Experimental Procedures

Figure 10.9: Photograph of the Fluidized Bed at the End of Operation with resin fully loaded with Copper

Figure 10.10: Photograph of the Regeneration of the resin with 2M Sulphuric Acid

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 59

Chapter Eleven: Results and Discussion

CHAPTER ELEVEN: RESULTS

AND

DISCUSSION

Preliminary experimental test work was done in order to determine the start up conditions for the column testing. The test work included:

• the determination of the effect of pH on the copper loading,

• the establishment of equilibrium profiles set at four pH set points,

• kinetic tests using two particle sizes of the TP 207 resin,

• mini column tests which involved testing based on two forms of the TP 207 resin,

• experimental determination ofUfand using three linear velocities to choose one linear, velocity to operate the fixed and fluidized ion exchange columns.

11.1 Influent Characteristics 11.1.1 Chemical Analysis

The influent solution was a pure cupric sulphate solution. Itwas decided that for the purpose of this test work, feed concentrations of 6 and 0.6 g/L copper would be used because these concen- tration range are mostly encountered for copper, in industry.

11.1.2 Void Volume Determination

The void volume (spaces between the resin particles when the resin is packed in a column) was determined. The procedure of the measurement was discussed in Section 10.3 and the calcula- tions are present in Appendix C2. A duplicate test was performed and the average value was used to ensure reliability. The void volume was experimentally determined to be 29.23 %. This value was used in Appendix C3 to calculate the minimum and settling velocity for fluidization.

11.2 Adsorbent

11.2.1 Resin Characterization

The batch of resin that was used for the purpose of this study had been used in previous investi- gations by Mintek. Although the theoretical capacity of the fresh resin is 1.2 mol/L (for diva- lent ions), the capacity of the used resin was experimentally determined to be 1 mol/L from equilibrium tests.

11.2.2 Particle Size Analysis

The procedure of the particle size analysis was discussed in Section 10.2 and the graphs for cu- mulative undersize and oversize distribution of the pre-screened TP 207 resin is present in Ap- pendix Cl for each run. The summary of the results are tabulated below.

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

~~~ ~

Chapter Eleven: Results and Discussion

TABLE 11.1: Summary of Particle Size Analysis Run Number Average per Run Lum]

1 720

2 716

3 740

4 725

5 730

6 735

7 730

8 730

Averaee particle size 728.25

Maximum 740

Minimum 716

Standard Deviation 7.759786448

Eight particle size distributions were determined for the TP 207 resin in the hydrogen form (Re- fer to Table 11.1). The finial average particle size was determined by adding all the average particle sizes for each run and dividing by the number of runs. This was determined to be 0.72825 mm. The value obtained was used in Appendix C3 to calculate the minimum and set- tling velocity for fluidization.

11.2.3 Water Retention Capacity

The water retention capacity is the amount of water that is retained inside the resin pores. The procedure of the measurement was discussed in Section 10.4 and the calculations are presented in Appendix C4. A duplicate test for water retention capacity was determined and the average value was taken to ensure reliability. The water retention capacity was experimentally deter- mined to be 44.8 %.

11.3 Preliminary Test Work

Preliminary test work was done to determine the effect of pH on copper loading onto the resin, as well as establish equilibrium isotherms at four different pH set points. Results from this phase of test work were used to plan the tests for the pilot plant more effectively.

11.3.1 pH Dependence of Metal Loadings

The experimental procedures for determining the effect of pH on the resin performance is dis- cussed in Section 10.5. Detailed experimental data and mass balance are present in Appendix D The effect of pH on copper loading onto TP 207 is given in Figure 11.1

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 61

Chapter Eleven: Results and Discussion

pH curve for Copper Solution

2.5 3 3.5 4 4.5 5

1.5 2

70 ,...---,--,---,-,-.,..-;-:---,-,---;----;-;---,---, 60-j-L.-.y---.L.L.L.t--4--i---H-+-'-;---l-.---r-t:d..,.-...-..,....:.~r--l-...r_r-,--,--j

~_Cl ⁵⁰-I-J--.---r+-L.:-++---....j-+-'--r--+-t--h.,J-6-++-"+--~t--'--+_t_I--T..,.__---l

-;; 40++--'---:-+--I----;-H-r+;l;.4¥'-rt--'--r--r-r--J+J-t-t~T'-_:__;_r-;--;-__;___:___---r--t-l

.5 30-I-J--.----'-rr-:-'-rn~+-r-'-+t-+-;-t-H-tt-ttt~l-l--.-+_t_r.-t_rr_r___---j

"'C

~ ²⁰

I

..J 10^+-t-irt-...'f'-+-I--f+-r+-t-r+t+++t-t-H-t-r-t-t--:--t-:-r-t-t-t-t-t-t-r--t-t-r-H--n-:TtTri

oVIII

o 0.5

pH ^--+-pH

Figure 11.1: Effect of pH on Copper Loading

The pH dependence curve for copper loading was measured by contacting TP 207 resin (in the hydrogen form), with the same amount of copper solution, at different pH values. It is evident from the optimum pH curve that the maximum copper loading may be achieved at a pH of above 3. Thus the pH of 3.0 would probably be the maximum pH that can be considered for copper extraction.

11.3.2 Ion Exchange Equilibrium Isotherms

Ion exchange equilibrium isotherms were established for copper on the TP 207 resin at four dif- ferent pH set points (Refer to Figure 11.2). The ion exchange equilibrium experiments were conducted according to the method outlined in Section 10.6. The experimental data and detailed results of the mass balance may be found in Appendix E for each equilibrium isotherm.

Summary of Equilibrium Plots

J .I- J

1-

Jl J J.

¹¹

I ~

1- t ^-I -r i · et

¹¹

- - --

I ^I

I I

., _I

_I

I

I

^I

.l.

^_

...

^.

.'. ',' f,'" r

^{I ' "}

_I

'I

^{I I I} [,;'

..

^'

_I

_{i I}

i I I ^I

1)-'·1 I ^I

I I I

^{I I}

I

^{I I}

I

^I

," I I I I I I I I I

70 60 50

~ ⁴⁰

Q) 30

o

20

10

o

o 2 3 4 5

Solution Concentration[gILl

6

• pH 3

• pH2.5 pH2 , ..•.. pH 1.5

Figure 11.2: Equilibrium Isotherm of TP 207 Resin [Favourable Isotherm]

The equilibrium curve that was determined showed that pH does have an effect on the TP 207 weak acid resin. It is evident from the curve that when the pH was maintained at 1.5, the maxi- mum loading of copper onto the TP 207 resin was 37 g/L. But when the pH was maintained at A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 62

Chapter Eleven: Results and Discussion

3, the maximum copper loaded onto the TP 207 resin was 61g/L. This confirms the pH tests that the optimum loading for copper on the TP 207 is at pH 3.

The separation factor is defined in Equation 11.1.

rC~2+

= CA (Q - qA) = x(l- y) (Equation 11.1)

H q.(C_o -CA) y(l-x)

Equation 11.1 can be used to classify the equilibrium behaviour into the following categories:

• Strongly favourable (with r ::: 0.3); in the limiting case, irreversible (r=O)

• Linear (r=l)

• Non Linear (0.3 <r< 10)

• Strongly unfavourable ( r> 10)

From the results calculated for this parameter at pH 3 and pH 2.5, the separation factor was less than 0.3 therefore from above criteria the equilibrium is strongly favourable. The distribution factor was also calculated. For each of the equilibrium curve Langmuir and Freundlich equilib- rium plots were determined (Refer to Appendix E for detailed calculations).

11.3.2.1 The Langmuir Isotherm for Equilibrium Curve at pH 3 From the Langmuir expression and taking the reciprocals:

qe =

(1

ab*C+bC:) (Equation 11.2)

1+b

*

C_e

= (Equation 11.3)

qe ab*C e

- - - + b*Ce (Equation 11.4)

ab*C e ab*C e

1 1 1

- = - -+ - (Equation 11.5)

qe ab*C e a

Likening Equation 11.5 to a "y = mx+c" straight line plot, a graph of (lIqe) against (liCe) will generate a y-axis intercept = (l/a) and a gradient= (l/ab intercept), if the equilibrium conforms to this relationship.

AComparative Study of Contacting Equipment for the Recovery of Copper from a Cupric SUlphate

Solution 63

Chapter Eleven: Results and Discussion

The LangmuirPlot

•

.... P""'

.... -,

_I

•

I I I

I I

I I I

0.04 0.03

Q)

Q 0.02 0.01

o

o 10 20

1/Ce

30

• experimental - Linear (experimental) 401/Qe= 0.0003(1/Ce)+0.0165

R²= 0.685 Figure 11.3: Langmuir Isotherm for Equilibrium Curve at pH 3

Fitting Parameters for the Langmuir Isotherm are present in Table 11.2.

TABLE 11.2: Fitting Parameters for Langmuir Isotherm at pH 3

a 60.606

b 55

r 0.827

Langmuir Model:

ab*C e 3333.33*Ce (E . 116)

qe = (1+bCJ = (1+55CJ quation .

11.3.2.2 The Freundlich Isotherm for Equilibrium Curve at pH 3 From the Freundlich expression and taking logs:

qe = KrCel/n (Equation 11.7)

log(qe) = 10g(K r )+10g(CeIln ) (Equation 11.8) 10g(qe)= 10g(K r

)+ (11

_{n)logC e} (Equation 11.9)

Likening Equation 11.9 to a fly = rnx+c" a straight-line plot, a graph of (log qe) against (log Ce) will generate a gradient= 1/n and y-axis intercept = log (Kr), if the equilibrium conforms to this relationship.

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 64

Chapter Eleven: Results and Discussion

The Freundlich Plot

oQ)

~

•

J

I^I

I

^{I I I}

U

^{I II}

• experimental

--Linear (experimental)

-2 -1.5 -1 -0.5

log Ce

o 0.5

log Qe=0.1072log Ce+ 1.7208 R²=0.7995

I

Figure 11.4: Freundlich Isotherm for Equilibrium Curve at pH 3 Fitting Parameters for the Freundlich Isotherm are presentinTable 11.3

TABLE 11.3: Fitting Parameters for Freundlich Isotherm at pH 3

l/n 0.1072

K

r 52.578

r 0.89

Freundlich Model:

qe =KrCel/n = 52.6C e^O.1 (Equation 11.10)

Equilibrium Curve: pH 3

I I ~I I I_ -40.

...I

^I

j ^-

..

_I

.-

^-I_I ^II ^II

I ^I

I I

I ^,

Solution Concentration[gILl 70

60 50

~ 40

o 30 20 10

o

o 2 3 4 5 6

--+-- Qe: Elution

• Langmuir Plot .. Freundlich Plot

Figure 11.5: A Comparison of Experimental Data with the Langmuir and Freundlich Plots atpH3

The above analysis was repeated for the three other pH values and the final results are summa- rized in the graphs below with a tabulation of the final models in Table 11.4.

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 65

Chapter Eleven: Results and Discussion

Equilibrium Curve: pH 2.5

.----+ ^-

-

^f-C f----'--...-.1-'

~ I)"

~

70 60 50

Q) 40

o

30 20 10

o

o 2 3 4 5 6

Solution Concentration [giLl --+ Qe: Elution Langmuir Plot .. Freundlich Plot

Figure 11.6: A Comparison of Experimental Data with the Langmuir and Freundlich Plots at pH 2.5

Equilibrium Curve: pH 2

I

- - -.

I~---===F~ 1

%"

,

1/

60 50 40

Q) 30

o 20 10

o

o 1 2 3 4

Solution Concentration [gILl

5 6

--- Qe: Elution Langmuir Plot .. Freundlich Plot

Figure 11.7: A Comparison of Experimental Data with the Langmuir and Freundlich Plots at pH2

Equilibrium Curve: pH 1.5

I ^-H-~I--~

... d"f- I

f"-

1 I

I

. /

/ '

I I I I

50 40

~ ³⁰ 20 10

o

o 2 3 4

Solution Concentration [gILl

5 6

- . - Qe: Elution - -. - Langmuir Plot

.. Freundlich Plot

Figure 11.8:A Comparison of Experimental Data with the Langmuir and Freundlich Plots at pH 1.5

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 66

Chapter Eleven: Results and Discussion

From the Langmuir and Freundlich plots, it is evident that both adsorption models resulted in a reasonably good correlation between statistical fit and the experimental data, with the Langmuir model fitting the experimental data slightly better than the Freundlich model.

TABLE 11.4: Final Results and Fitting Parameters for Equilibrium Curves Fitting Parameter:

Langmuir Curve Freundlich pH

Langmuir Freundlich Curve

a=60.606 1/n =0.10 3333.33*Cc qc = 52.6 Cc0.1

3 b=55 Kf=52.6 qe =

(1 + 55Cc) r=0.82 r =0.89

a=57.47 1/n =0.1386 833.32 * Cc qc = 46.76 Cc0.14

2.5 qe=

b=14.5 Kf=46.76 (1 + 14.5CJ

r=0.99 r =0.92

a=54.348 1/n =0.1869 232.56 * Cc qc = 38.9 Cc0.187

2 qe -

b=4.279 Kf=38.9 - (1 +4.28CJ

r=0.99 r =0.9

a=56.497 1/n =0.46 24.86 * Cc qc = 18.6 Cc0.46

1.5 qe-

b=0.44 Kf=18.625 - (1 +0.44CJ

r=0.99 r =0.97

11.3.3 Kinetic Tests

Kinetic tests were conducted with feed solution concentrations of 6 and 0.6 g/L. The resin was screened and two particle sizes 850f1.mand 600f1.m were used to find the effect of particle size on the rate of adsorption of copper onto the TP 207 resin, at a pH set point of 3. The experimen- tal procedure employed for the kinetic tests is described in Section 10.7. The experimental data and detailed results of the mass balance may be found in Appendix F.

Figure 11.9 is the kinetic response for particle size 850 micrometers and initial solution concen- tration of 6 g/L. The procedure was repeated for concentration of 0.6 g/L and particle diameter 600 micrometers(Refer to Appendix F).

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 67

Chapter Eleven: Results and Discussion

Kinetic Response for 850 microns and 6 g/L

1

1

;

I:

^I

_I

^{I I1 1I}

I

! III

11: I

I I I

I

^{11 I} I

~ll

I I ^!

^{, 11}

IAi

! I

'+1 ¹¹

¹¹

^{I I I Ill: I}

2

• [C'l

i

25 30

10 15 20

Time [hours]

5

o o :r

El

c: 1.5

~o C~ ^0.5

<3

Figure 11.9: Kinetic Response for 850.um and Initial Concentration 6 g/L

The integral method(Refer to Chapter Three, Section3.5.2), uses trial and error procedures to find the reaction order. This method was used to determine the order of the reaction for each kinetic response. Figure 11.9 was modelled into a first and second order reaction curve.

First Order Reaction for 850 microns and 6 g/L

Time [hours]

8

-r---r-r\---,,---,-I.,....-,- ^11-

~l,....,..:..---,-I^"'-'11"'--1 '3'6

I

I _ ....1"•...-I I ^I

U .... ~^{. . .}~ LJ.

"ll

^{1 1}

g

^4+-r.L!:.T:.lo-r",,'-'-'q.-J-Hf-+-I+-+-+-+++J-.L,++-H+-r-r-1--1

~2~~1

^{1 1 I1}

^!

J

1 1

1

1

¹¹

I ·

Experimental

o-t-L...L.L..l.-,-...l-....L.J'-+-LLL..L+-L.L.L..LL...L.L...L.L+J...L.J....L..< - Linear (Experimental)

o 5 10 15 20 25 30

In(Cuo/Cu)

=

0.1845t + 3.0708 R²

=

^0.4293

Figure 11.10: First Order Reaction Kinetics for 850.um and Initial Concentration 6 glL

Second Order Reaction for 850 microns and6g/L

• Experimental -Linear

(Experimental)

30

1/Cu

=

^{2.6431t+9.6295}

R²

=

^0.6638

I

25

10 15 20

Time [hours]

5

~:::l ⁴⁰.j-+-J-~~4-'bJ,.o!~...Ll..Ll..LL-h---l--l--:-~'--l

...

Figure 11.11: Second Order Reaction Kinetic for 850.um and Initial Concentration 6 glL

A Comparative Study of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

Solution 68

Chapter Eleven: Results and Discussion

By plotting lICu versus time (for second order reactions only), gave a better fit than the first order reaction (Refer to Figure 11.10 and Figure 11.11) therefore the order of the reaction was determined experimentally to be 2. The procedure was repeated for both concentrations and par- ticle sizes. The slope of the linear plot rendered the mass transfer coefficientk. The k value was used to predict the [Cu] and compare it to experimental [Cu]. These values correlate well (Refer to Appendix F). The mass transfer coefficient (k) values are summarized in Table 11.5 and Ta- ble 11.6.

TABLE 11.5: Mass Transfer Coefficient (k) for Diameter 850 pm Mass Transfer Coefficient (k) at 6 and 0.6 g/L

Concentration 6g/L 0.6 g/L

k: 1st order 0.1845 0.1769

k: 2nd order 2.6431 4.857

TABLE 11.6: Mass Transfer Coefficient (k) for Diameter 600 pm Mass Transfer Coefficient (k) at 6 and 0.6 g/L

Concentration 6 g/L 0.6 g/L

k: 1st order 0.2068 0.2496

k: 2nd order 5.6317 23.96

From the graphs below, one can compare how particle size has an effect on concentration, these results are shown in Figure 11.12 and Figure 11.13. The effect of particle size for the TP 207 resin at 850 pm and 600 pm are represented in Figure 11.12 for concentration 6 g/L. From this graph it is clearly seen that particle size has no effect for an initial concentration of 6 g/L.

Effect of Particle Diameter for 6 g/L

• ^I

,

I!I

I ..

¹¹

~ 2

...J

:S!! 1.5

§

~

c:

Q)g 0.5

8

⁰

o 5 10 15 20

Time [hoursl

25 30

• Diameter: 850 microns

• Daimeter: 600 microns

Figure 11.12: Effect of particle diameter at initial concentration of 6 g/L

ACo~parativeStudy of Contacting Equipment for the Recovery of Copper from a Cupric Sulphate

SolutIOn 69